EnglishEdward
Deity
I do not know why the pollsters were so wrong, keep being so wrong. I did hear that one in particular oversampled older women, was the criticism against that particular poll.
The demonization of Trump by the democrats probably contributed to how wrong the polls are election after election there. More people will refuse to indulge pollsters because they (most of the media, where the polls are published) are with the enemy. It is not fear of speaking out, mind you, it is disgust at them. That's what happens in these situations. Look at the (let's be ironic) polls about the credibility of the media...
I don't think many opinion pollsters have a reliable methodology for those who won't give an opinion.
I suspect most just assume that their vote distribution is the same as those who respond.
I am not surprised that Donald won, as I always thought there would be a number of shy Trump
voters in much the same way as there were in the UK shy tory voters and shy Leave voters.
However the margin of his victory is larger than I expected.
I suspect you are right, the emotional and rhetorical polarisation of the issue increased the shy vote.